With the rapid increasing need for enterprises to accommodate information communication between the enterprises, between the enterprises and customers, or between enterprises and other information providers, the enterprises usually have to invest much capital on hardware and software for information management. Hardware integrated with network infrastructure may include web servers, mail servers, application servers, file servers, storage servers, and the like; software may include operation systems for the aforementioned servers, public programs, service program, web browsers, and other application programs required by users.
Blade server, which is an advanced server among the aforementioned servers, takes up small space and exhibits flexibility in controlling the resource capacity. It provides users with a simple way to expand or upgrade by plugging the blade server in a slot of a chassis.
The blade server is a small-scale server, which is generally secured in a tailor-made rack and can be stacked in a row or a column such as dishes or books. The power system and the network connecting device are for shared use in the blade server. Since the blade server consumes less power and occupies less space than a conventional individual server, it helps the enterprises reduce the operation cost. The blade server usually serves as a web server. In case new functions are provided, the blade server can be more widely used; for example, the blade server can be electrically connected with a cluster expansion card that is plugged in another slot of the chassis to enable cluster calculation, or with a network connecting card to enable local area network (LAN) connection.
Although the conventional blade server can significantly reduce its occupied space, the expansion cost thereof is increased. The chassis comprises a plurality of slots for accommodating blade servers. In order to store data, the blade server needs to be electrically coupled to at least one storage unit such as hard disk. The storage unit can be plugged into a specific slot formed on the chassis, or can be integrally formed on a substrate of the blade server.
However, the above plug-in connecting method between the storage unit and the blade server has a drawback that, the provision of the specific slot for storage unit decreases the number of slots for blade servers on the chassis. Moreover, the formation of both the slots for blade servers and the specific slot for storage unit on the chassis makes the fabrication more complicated and also increases the fabrication cost. This also presets the number of the slot for storage unit by the manufacturer, preventing adjustment according to different user requirements. Regarding the integral formation of the storage unit on the substrate of the blade server, a small-scale storage unit is typically used to comply with the size of the blade server, which however costs more than a large-scale storage units. In addition, the expandability by the above connecting methods is not good, and the methods are somewhat complex to implement.
Therefore, the problem to be solved here is to provide an expansion device for storage units, which allows good expandability and good compatibility between storage units using different standards.